Cyanobacterial Harmful Algal Blooms : State of the Science and Research Needs, Vol. 619

Cyanobacteria are single-celled organisms that live in fresh, brackish, and marine water. They use sunlight to make their own food. In warm, nutrient-rich environments, microscopic cyanobacteria can grow quickly, creating blooms that spread across the water’s surface and may become visible. Because of the color, texture, and location of these blooms, the common name for cyanobacteria is blue-green algae. However, cyanobacteria are related more closely to bacteria than to algae. Cyanobacteria are found worldwide, from Brazil to China, Australia to the United States. In warmer climates, these organisms can grow year-round. Scientists have called cyanobacteria the origin of plants, and have credited cyanobacteria with providing nitrogen fertilizer for rice and beans. But blooms of cyanobacteria are not always helpful. When these blooms become harmful to the environment, animals, and humans, scientists call them cyanobacterial harmful algal blooms (CyanoHABs). Freshwater CyanoHABs can use up the oxygen and block the sunlight that other organisms need to live. They also can produce powerful toxins that affect the brain and liver of animals and humans. Because of concerns about CyanoHABs, which can grow in drinking water and recreational water, the U.S. Environmental Protection Agency (EPA) has added cyanobacteria to its Drinking Water Contaminant Candidate List. This list identifies organisms and toxins that EPA considers to be priorities for investigation. Reports of poisonings associated with CyanoHABs date back to the late 1800s. Anecdotal evidence and data from laboratory animal research suggest that cyanobacterial toxins can cause a range of adverse human health effects, yet few studies have explored the links between CyanoHABs and human health. Humans can be exposed to cyanobacterial toxins by drinking water that contains the toxins, swimming in water that contains high concentrations of cyanobacterial cells, or breathing air that contains cyanobacterial cells or toxins (while watering a lawn with contaminated water, for example). Health effects associated with exposure to high concentrations of cyanobacterial toxins include: * stomach and intestinal illness; * trouble breathing; * allergic responses; * skin irritation; * liver damage; and * neurotoxic reactions, such as tingling fingers and toes. Scientists are exploring the human health effects associated with long-term exposure to low levels of cyanobacterial toxins. Some studies have suggested that such exposure could be associated with chronic illnesses, such as liver cancer and digestive-system cancer. This monograph contains the proceedings of the International Symposium on Cyanobacterial Harmful Algal Blooms held in Research Triangle Park, NC, September 6-10, 2005. The symposium was held to help meet the mandates of the Harmful Algal Bloom and Hypoxia Research and Control Act, as reauthorized and expanded in December 2004. The monograph will be presented to Congress by an interagency task force. The monograph includes: 1) A synopsis which proposes a National Research Plan for Cyanobacteria and their Toxins; 2) Six workgroup reports that identify and prioritize research needs; 3) Twenty-five invited speaker papers that describe the state of the science; 4) Forty poster abstracts that describe novel research.

Cyanobacteria are single-celled organisms that live in fresh, brackish, and marine water. They use sunlight to make their own food. In warm, nutrient-rich environments, microscopic cyanobacteria can grow quickly, creating blooms that spread across the water’s surface and may become visible. Because of the color, texture, and location of these blooms, the common name for cyanobacteria is blue-green algae. However, cyanobacteria are related more closely to bacteria than to algae. Cyanobacteria are found worldwide, from Brazil to China, Australia to the United States. In warmer climates, these organisms can grow year-round.

Scientists have called cyanobacteria the origin of plants, and have credited cyanobacteria with providing nitrogen fertilizer for rice and beans. But blooms of cyanobacteria are not always helpful. When these blooms become harmful to the environment, animals, and humans, scientists call them cyanobacterial harmful algal blooms (CyanoHABs).

Freshwater CyanoHABs can use up the oxygen and block the sunlight that other organisms need to live. They also can produce powerful toxins that affect the brain and liver of animals and humans. Because of concerns about CyanoHABs, which can grow in drinking water and recreational water, the U.S. Environmental Protection Agency (EPA) has added cyanobacteria to its Drinking Water Contaminant Candidate List. This list identifies organisms and toxins that EPA considers to be priorities for investigation.

Reports of poisonings associated with CyanoHABs date back to the late 1800s. Anecdotal evidence and data from laboratory animal research suggest that cyanobacterial toxins can cause a range of adverse human health effects, yet few studies have explored the links between CyanoHABs and human health.

Humans can be exposed to cyanobacterial toxins by drinking water that contains the toxins, swimming in water that contains high concentrations of cyanobacterial cells, or breathing air that contains cyanobacterial cells or toxins (while watering a lawn with contaminated water, for example). Health effects associated with exposure to high concentrations of cyanobacterial toxins include:

• stomach and intestinal illness;
• trouble breathing;
• allergic responses;
• skin irritation;
• liver damage; and
• neurotoxic reactions, such as tingling fingers and toes.

Scientists are exploring the human health effects associated with long-term exposure to low levels of cyanobacterial toxins. Some studies have suggested that such exposure could be associated with chronic illnesses, such as liver cancer and digestive-system cancer.

This monograph contains the proceedings of the International Symposium on Cyanobacterial Harmful Algal Blooms held in Research Triangle Park, NC, September 6-10, 2005. The symposium was held to help meet the mandates of the Harmful Algal Bloom and Hypoxia Research and Control Act, as reauthorized and expanded in December 2004. The monograph will be presented to Congress by an interagency task force.

The monograph includes:

1) A synopsis which proposes a National Research Plan for Cyanobacteria and their Toxins;

2) Six workgroup reports that identify and prioritize research needs;

3) Twenty-five invited speaker papers that describe the state of the science;

4) Forty poster abstracts that describe novel research.

Front Matter....Pages I-XXIII An Overview of the Interagency, International Symposium on Cyanobacterial Harmful Algal Blooms (ISOC-HAB): Advancing the Scientific Understanding of Freshwater Harmful Algal Blooms....Pages 1-16 A Synopsis of Research Needs Identified at the Interagency, International Symposium on Cyanobacterial Harmful Algal Blooms (ISOC-HAB)....Pages 17-43 Occurrence of Cyanobacterial Harmful Algal Blooms Workgroup Report....Pages 45-103 A world overview — One-hundred-twenty-seven years of research on toxic cyanobacteria — Where do we go from here?....Pages 105-125 Toxic Cyanobacteria in Florida Waters....Pages 127-137 Nebraska Experience....Pages 139-152 Cyanobacterial Toxins in New York and the Lower Great Lakes Ecosystems....Pages 153-165 Occurrence Workgroup Poster Abstracts....Pages 167-184 Causes, Prevention, and Mitigation Workgroup Report....Pages 185-215 Nutrient and other environmental controls of harmful cyanobacterial blooms along the freshwater–marine continuum....Pages 217-237 Global warming and cyanobacterial harmful algal blooms....Pages 239-257 Watershed management strategies to prevent and control cyanobacterial harmful algal blooms....Pages 259-273 Cyanobacterial toxin removal in drinking water treatment processes and recreational waters....Pages 275-290 Causes, Mitigation, and Prevention Workgroup Posters....Pages 291-315 Cyanotoxins Workgroup Report....Pages 317-381 Toxin types, toxicokinetics and toxicodynamics....Pages 383-415 The genetics and genomics of cyanobacterial toxicity....Pages 417-452 Determining important parameters related to cyanobacterial alkaloid toxin exposure....Pages 453-463 Toxins Workgroup Poster Abstracts....Pages 465-468 Analytical Methods Workgroup Report....Pages 469-481 Cyanotoxins: sampling, sample processing and toxin uptake....Pages 483-499 Field methods in the study of toxic cyanobacterial blooms: results and insights from Lake Erie Research....Pages 501-512 Conventional laboratory methods for cyanotoxins....Pages 513-537 Emerging high throughput analyses of cyanobacterial toxins and toxic cyanobacteria....Pages 539-557 Analytical Methods Workgroup Poster Abstracts....Pages 559-578 Human Health Effects Workgroup Report....Pages 579-606 Health effects associated with controlled exposures to cyanobacterial toxins....Pages 607-612 Cyanobacterial poisoning in livestock, wild mammals and birds – an overview....Pages 613-637 Epidemiology of cyanobacteria and their toxins....Pages 639-649 Human Health Effects Workgroup Poster Abstracts....Pages 651-654 Ecosystem Effects Workgroup Report....Pages 655-674 Cyanobacterial toxins: a qualitative meta–analysis of concentrations, dosage and effects in freshwater, estuarine and marine biota....Pages 675-732 Cyanobacteria blooms: effects on aquatic ecosystems....Pages 733-747 Ecosystem Effects Workgroup Poster Abstracts....Pages 749-757 Risk Assessment Workgroup Report....Pages 759-829 Effective doses, guidelines & regulations....Pages 831-853 Economic cost of cyanobacterial blooms....Pages 855-865 Integrating human and ecological risk assessment: application to the cyanobacterial harmful algal bloom problem....Pages 867-883 Toxin mixture in cyanobacterial blooms – a critical comparison of reality with current procedures employed in human health risk assessment....Pages 885-912 Back Matter....Pages 913-949 With the ever-increasing incidence of harmful cyanobacterial algal blooms, this monograph has added urgency and will be essential reading for all sorts of researchers, from neuroscientists to cancer research specialists. The volume contains the proceedings of the 2005 International Symposium on Cyanobacterial Harmful Algal Blooms, and has been edited by H. Kenneth Hudnell, of the US Environmental Protection Agency. It contains much of the most recent research into the subject.